The present invention relates to a gasoline dispensing system and method and, more particularly, to such a system and method in which relatively low flow rates are inhibited.
In fluid flow systems, such as gasoline services station installations, the gasoline is pumped from an underground storage tank, through a conduit, or tube, to a dispenser unit, and through a hose extending from the dispenser unit to a nozzle for dispensing the gasoline into a vehicle tank. A manually operable valve is provided on the nozzle to enable the customer to initiate the dispensing and control the flow of the gasoline during the complete dispensing cycle.
Although a system valve is also provided to control the gasoline flow, the system operates for most of the time at the full flow rate. However, when the system does operate at a low flow rate, such as when the customer partially shuts off the nozzle valve near the end of the dispensing cycle and/or tops off the vehicle tank, a cost-competitive flow meter is often inaccurate. This is significant since it is important that the customer be charged for exactly the amount of gasoline dispensed. Also, certain government regulations require relatively high accuracy of the metered flow during all flow conditions.
Therefore what is needed is a fluid flow system of the above type which inhibits the fluid flow below a predetermined rate and thus insures high accuracy metering of the flow that is metered.